perio aetiology Flashcards
What are local plaque retention factors? (4 points)
- Calculus
- Restoration margins
- Crowding
- Mouth breathing
What are systemic modifying factors for plaque/gingivitis? (2 points)
Sex hormones
Medication
What characteristics define gingival health? (3 points)
- Knife edge, scalloped gingival margin
- Stippling (in about 30%)
- Pink
What are defining features of periodontitis? (2 points)
Irreversible loss of attachment of the epithelium
Low bone
Does gingivitis always progress to periodontitis?
no
Once periodontitis is initiated, is progression of the attachment loss episodic or continuous?
- Can be either
- Hard to judge how fast it goes once initiated
- Different sites within the same mouth may be affected to markedly varying degrees
What is the rate of progression loss of attachment in periodontitis like?
Generally very slow (0.05-0.1mm per year) but this is highly variable
What is biofilm?
One or more communities of microorganisms, embedded in a glycocalyx, attached to a solid surface
What are 4 properties of biofilm?
- Provide protection for colonising species from competing organisms and environment (host defences, antibiotics)
- Facilitate uptake of nutrients and removal of metabolic products
- Development of appropriate physiochemical environment e.g. pH, O2 concentration
- Communication between bacteria
What 2 features can increase the bacteria’s virulence?
Ability to colonise and compete in an ecological niche
Ability to evade host defences
How can bacteria evade host defences? (4 points)
- Degrade host immunoglobin and complement
- Leukotoxin production
- Tissue invasion
- Inhibition of antibody synthesis
Does a specific bacteria cause periodontal disease?
Not one single bacteria has been proven causative
What is possible evidence needed to prove that a specific bacteria is the cause of something? (5 points)
- Presence in elevated numbers at diseased sites
- Reduced numbers following periodontal therapy
- Presence of an elevated specific immune response
- Production of virulence factors
- Evidence from animal models
Which complex of bacteria makes you likely to have perio problems? (3 points)
- P. gingivalis
- B. forsythus
- T. denticola
Can periodontitis occur without the presence of bacteria ?
No
Periodontitis is a synergistic infection. What does this mean?
Not just one bacteria that causes it (plaque ecology is important)
What are examples of mechanisms that contribute to the host response against perio problems? (4 points)
- Saliva
- Epithelium (physical barrier, shedding of cells, production of inflammatory mediators)
- GCF
- Inflammatory and immune responses
Which type of cell is the initial periodontal lesion composed of?
T lymphocytes
The initial periodontal lesion is compromised mainly of T lymphocytes. Which cells predominate in a later stage? (2 points)
B cells
Plasma cells
Antibody is produced locally at the initial periodontal lesion. What is its likely role?
Likely protective role
What are the protective functions of an antibody? (4 points)
- Inhibition of adhesion/invasion
- Complement activation
- Neutralisation of toxins
- Opsonisation and phagocytosis
What are MMP’s? (2 points)
- Matrix metalloproteinases are a family of zinc and calcium dependent proteolytic enzymes, which include collagenases
- In periodontitis, Matrix degradation is largely a result of MMP’s secreted by host inflammatory cells
What are general risk factors of periodontitis? (6 points)
smoking
diabetes
stress
drugs
systemic disease
nutrition
What are risk determinants of periodontal disease? (3 points)
- Genetics
- Socioeconomic status
- Gender
What are anatomical risk factors that can cause periodontitis? (4 points)
- Enamel pearls/projections
- Grooves
- Furcations
- Gingival recession
What tooth positions are predisposed to perio problems? (5 points)
- Malalignment
- Crowding
- Tipping
- Migration
- Occlusal forces
What are iatrogenic risk factors for periodontitis? (4 points)
- Restoration overhangs
- Defective crown margins
- Poorly designed partial dentures
- Orthodontic appliances
Why can smoking contribute to periodontitis? (5 points)
- Vasoconstriction of gingival vessels and increased gingival keratinisation
- Impaired antibody production
- Depressed numbers of Th lymphocytes
- Impaired PMN function
- Increased production of pro-inflammatory cytokines
What is the primary aetiological agent in inflammatory periodontal disease?
Microbial plaque
